Casey Helm, of Green Island School, asks :-

What do nerve cells look like?

Dorothy Oorschot, a neuroscientist and anatomist at the University of Otago, responded.

Each nerve cell looks a bit like an octopus. The soma of a nerve cell is the control centre and is positioned like the head of an octopus, being round or oval but only about 0.02mm across. Emerging from this centre are "arms" called "processes" that look somewhat like the tentacles of an octopus. In a nerve cell there are two types of "processes" called dendrites or axons. Dendrites convey information like touch and pain from your skin towards the soma of a nerve cell. Axons convey this information from the soma of a nerve cell to the next nerve cells and sometimes to muscle cells. An axon of a large nerve cell can be more than a metre long. For example, a nerve axon to a muscle in your foot starts in your spinal cord in your lower back and travels all the way down your leg to your foot.

One nerve cell talks to other nerve cells using special contacts called synapses. The special contacts with muscle cells are called neuromuscular junctions. The synapses look a bit like the suction pads on the tentacles of an octopus. Each nerve cell has lots of separate synapses made onto its dendrites and a few on its soma. Each nerve cell usually makes thousands of synapses with other nerve cells.

Your brain is made up of millions of nerve cells, or "octopuses". The nerve cells are intermingled and intertwined and synapse with nearby and distant nerve cells. Your brain is thus a bit like a dense hedge of nerve cells all intertwined. You may think this means that your brain is 'messy' in terms of the big picture of nerve cells. Yet, it is actually exquisitely well ordered and patterned. The challenge is to find the order and the pattern. This is what some research scientists are doing now.